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Finding the Fourth Proportional to 78.77, 118.19 and 61.79

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Solution

The fourth proportional to 78.77, 118.19 and 61.79 is: 92.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.77 : 118.19 = 61.79 : x
  2. Step 2: Convert to fraction form
    78.77/118.19 = 61.79/x
  3. Step 3: Cross multiply
    78.77x = 118.19 × 61.79
  4. Step 4: Simplify right side
    78.77x = 7,302.96
  5. Step 5: Solve for x
    x = 7,302.96/78.77
  6. Step 6: Final answer
    x = 92.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.